Endocrinology — MCQs

Endocrinology Indian Medical PG Practice Questions and MCQs

Question 1221: Gallstones are associated with which neuroendocrine tumor?

A. Insulinoma
B. VIPoma
C. Somatostatinoma (Correct Answer)
D. Glucagonoma

Explanation: The correct answer is **Somatostatinoma**. **1. Why Somatostatinoma is correct:** Somatostatinomas are rare neuroendocrine tumors (NETs) that secrete excessive amounts of **somatostatin** [1]. Somatostatin is a potent inhibitory hormone. In the biliary system, it inhibits the release of **Cholecystokinin (CCK)** and directly suppresses gallbladder contractility. This leads to profound **biliary stasis**, resulting in the formation of gallstones (cholelithiasis). The classic "Somatostatinoma Syndrome" triad consists of: * **Diabetes Mellitus** (due to inhibition of insulin/glucagon) * **Cholelithiasis** (due to biliary stasis) * **Steatorrhea** (due to inhibition of pancreatic enzymes and bicarbonate) **2. Why the other options are incorrect:** * **Insulinoma:** Presents with Whipple’s triad (hypoglycemia symptoms, low plasma glucose, and relief upon glucose administration). It is not associated with gallstones. * **VIPoma:** Characterized by **WDHA Syndrome** (Watery Diarrhea, Hypokalemia, and Achlorhydria). It causes massive secretory diarrhea but does not directly cause gallstones. * **Glucagonoma:** Presents with the "4Ds": **D**ermatitis (Necrolytic Migratory Erythema), **D**iabetes, **D**eep vein thrombosis, and **D**epression. **3. High-Yield Clinical Pearls for NEET-PG:** * **Most common location:** Somatostatinomas are most frequently found in the **pancreas** (head) or the **duodenum**. * **Psammoma bodies:** Duodenal somatostatinomas are uniquely associated with the presence of psammoma bodies on histology. * **Association:** Often associated with **MEN-1** and **Neurofibromatosis type 1 (NF-1)**. * **Octreotide Link:** Long-term therapeutic use of Octreotide (a somatostatin analogue) also carries a high risk of gallstone formation for the same physiological reasons.

Question 1222: Which of the following statements regarding insulin resistance in diabetic patients is FALSE?

A. It is more common with huminsulin. (Correct Answer)
B. It may occur in the presence of infections.
C. It may be due to antibodies to insulin.
D. Use of glucocorticoids may be useful in severe cases.

Explanation: Explanation: 1. Why Option A is the correct (False) statement: Insulin resistance due to antibody formation is significantly less common with human insulin (Huminsulin) compared to older animal-derived insulins (bovine or porcine) [2]. Human insulin is produced via recombinant DNA technology and is identical to endogenous human insulin, making it far less immunogenic. Animal insulins differ by one (porcine) or three (bovine) amino acids, which triggers the production of anti-insulin antibodies (IgG), leading to immune-mediated insulin resistance [2]. 2. Analysis of other options: * Option B (True): Infections trigger the release of counter-regulatory hormones like cortisol, glucagon, and catecholamines. These hormones induce a state of acute insulin resistance and hyperglycemia [3]. * Option C (True): High titers of circulating anti-insulin IgG antibodies can neutralize injected insulin, preventing it from binding to receptors [2]. This is the classic definition of "immune insulin resistance." * Option D (True): In severe cases of immune-mediated insulin resistance (where antibody titers are very high), glucocorticoids are used therapeutically to suppress the immune system and reduce antibody production, thereby restoring insulin sensitivity [3]. 3. NEET-PG High-Yield Pearls: * Definition: Clinical insulin resistance is defined as a daily requirement of >200 units of insulin in the absence of ketoacidosis or infection. * Most Immunogenic Insulin: Bovine insulin (highest amino acid variance). * Least Immunogenic Insulin: Human insulin and insulin analogues (Lispro, Aspart). * Acanthosis Nigricans: A key clinical marker of non-immune insulin resistance (Type 2 DM/Metabolic Syndrome) [1].

Question 1223: A 33-year-old woman has experienced episodes of fatigue, pleural effusion, pericardial effusion, carpal tunnel syndrome, and macrocytic anemia. What is the best test for diagnosis?

A. Anti-beta 2 phospholipid antibodies
B. Anti-smith antibody
C. Antinuclear antibody
D. Assay for thyroid hormones (Correct Answer)

Explanation: **Explanation:** The clinical presentation of fatigue, serous effusions (pleural and pericardial), carpal tunnel syndrome (CTS), and macrocytic anemia is a classic constellation of symptoms for **Hypothyroidism**. 1. **Why Option D is correct:** * **Effusions:** Hypothyroidism leads to increased capillary permeability and decreased lymphatic drainage, causing protein-rich fluid accumulation in the pericardial and pleural spaces. * **Carpal Tunnel Syndrome:** Deposition of glycosaminoglycans (mucopolysaccharides) in the connective tissue of the wrist causes compression of the median nerve. * **Macrocytic Anemia:** While hypothyroidism can cause normocytic anemia, it is a well-known cause of non-megaloblastic macrocytosis. Additionally, it is frequently associated with Pernicious Anemia (Autoimmune Polyendocrine Syndrome). * **Diagnosis:** An assay for thyroid hormones (specifically **Elevated TSH** and Low Free T4) is the definitive gold standard for diagnosis [1]. In hypothyroidism due to disease of the thyroid gland, low T3 and T4 are associated with high TSH [1]. 2. **Why other options are incorrect:** * **Options A, B, and C:** These tests (Anti-phospholipid, Anti-Smith, and ANA) are used to diagnose Systemic Lupus Erythematosus (SLE) or APS. While SLE can cause serous effusions and fatigue, it typically presents with inflammatory markers (malar rash, arthritis, nephritis) and does not typically cause carpal tunnel syndrome or macrocytic anemia. **High-Yield Clinical Pearls for NEET-PG:** * **Most common cause of Hypothyroidism:** Hashimoto’s Thyroiditis (associated with Anti-TPO antibodies). * **Dermatological finding:** Non-pitting edema (Myxedema) due to hyaluronic acid deposition. * **Reflexes:** "Hung-up" or delayed relaxation of the deep tendon reflexes (Woltman sign) is a pathognomonic physical finding. * **Lipid Profile:** Hypothyroidism is a secondary cause of Hypercholesterolemia (due to decreased LDL receptor expression).

Question 1224: What is the drug of choice in an 80-year-old patient presenting with hyperglycemia and ketoacidosis?

A. Oral hypoglycemic drugs
B. Intermediate acting insulin
C. Oral drug with intermediate acting insulin
D. Short acting insulin (Correct Answer)

Explanation: The clinical presentation of hyperglycemia combined with ketoacidosis indicates a diagnosis of **Diabetic Ketoacidosis (DKA)** [1]. DKA is a medical emergency characterized by an absolute or relative deficiency of insulin, leading to hyperglycemia, ketonemia, and metabolic acidosis [4]. **Why Short-Acting Insulin is Correct:** The cornerstone of DKA management, regardless of the patient's age, is **Regular (Short-acting) Insulin** administered via a continuous intravenous infusion [2]. Short-acting insulin is preferred because: 1. **Rapid Onset:** It works immediately to inhibit lipolysis and ketogenesis. 2. **Titratability:** Its short half-life allows for precise dose adjustments based on hourly blood glucose and anion gap monitoring. 3. **Safety:** In an 80-year-old patient who may have underlying renal or cardiac comorbidities, the ability to quickly stop the insulin effect if hypoglycemia occurs is vital [3]. **Why Other Options are Incorrect:** * **Oral Hypoglycemic Drugs (A & C):** These are contraindicated in DKA. They are insufficient to reverse ketosis and cannot be used in acute, life-threatening metabolic crises. * **Intermediate-Acting Insulin (B & C):** Drugs like NPH have a delayed onset and a prolonged peak. They do not allow for the rapid titration required to manage the dynamic shifts in electrolytes and glucose seen during DKA treatment. **NEET-PG High-Yield Pearls:** * **Standard Protocol:** Start with an IV bolus of 0.1 U/kg, followed by a continuous infusion of 0.1 U/kg/hr. * **The Goal:** The primary goal in DKA is to **close the anion gap** (stop ketosis), not just normalize blood glucose [2]. * **Potassium Warning:** Never start insulin if serum potassium is **<3.3 mEq/L**, as insulin will shift potassium intracellularly, potentially causing fatal arrhythmias [5]. * **Fluid of Choice:** Initial resuscitation should always begin with **0.9% Normal Saline** [1].

Question 1225: Which of the following is a symptom of hypoglycemia?

A. Sweating (Correct Answer)
B. Bradycardia
C. Chest pain
D. Breathlessness

Explanation: **Explanation:** Hypoglycemia (blood glucose <70 mg/dL) triggers a dual-phase clinical response: **Autonomic (Neurogenic)** and **Neuroglycopenic** [1]. 1. **Why Sweating is Correct:** When blood glucose drops, the body activates the sympathetic nervous system and the adrenal medulla to release epinephrine and norepinephrine [2]. This "adrenergic surge" stimulates sweat glands (specifically via sympathetic cholinergic fibers), leading to **diaphoresis (sweating)** [3]. Other autonomic symptoms include tremors, palpitations, and anxiety. Sweating is a hallmark sign and is often the last autonomic symptom to be suppressed in patients with "hypoglycemia unawareness" (except in those on beta-blockers) [3]. 2. **Analysis of Incorrect Options:** * **B. Bradycardia:** Hypoglycemia typically causes **tachycardia** due to the compensatory catecholamine surge [2]. Bradycardia is not a standard feature. * **C. Chest Pain:** While severe tachycardia can trigger angina in patients with underlying CAD, chest pain is not a primary or diagnostic symptom of hypoglycemia. * **D. Breathlessness:** Dyspnea is not a classic symptom. Hypoglycemia primarily affects the CNS (confusion, seizures) and the autonomic system. **High-Yield NEET-PG Pearls:** * **Whipple’s Triad:** 1. Symptoms of hypoglycemia, 2. Low plasma glucose, 3. Relief of symptoms after glucose administration. * **Beta-Blockers Warning:** Non-selective beta-blockers can mask all autonomic symptoms of hypoglycemia (tachycardia, tremors) **except sweating**. * **Neuroglycopenic symptoms** (due to CNS glucose deprivation) include confusion, fatigue, seizures, and coma; these typically occur at lower glucose levels (<54 mg/dL) than autonomic symptoms [4].

Question 1226: The paradoxical response of Growth Hormone (GH) release to Thyrotropin-Releasing Hormone (TRH) is seen in which condition?

A. Prolactinoma
B. Acromegaly (Correct Answer)
C. Malnutrition
D. Pituitary adenoma

Explanation: In a healthy individual, Growth Hormone (GH) secretion is primarily regulated by GHRH (stimulatory) and Somatostatin (inhibitory). Thyrotropin-Releasing Hormone (TRH) normally has no effect on GH levels. However, in **Acromegaly**, the somatotroph cells of the pituitary adenoma undergo "dedifferentiation" or express receptors they normally wouldn't [1]. This leads to a **paradoxical rise in GH** following the administration of TRH or GnRH in approximately 50-80% of patients [1]. **Analysis of Options:** * **Acromegaly (Correct):** The neoplastic somatotrophs lose their physiological specificity, responding to TRH with a significant increase in GH [1]. This is a classic biochemical hallmark used in functional studies of the disease. * **Prolactinoma:** While often co-secreted with GH, a pure prolactinoma typically shows an increase in Prolactin, not a paradoxical GH response to TRH [1]. * **Malnutrition:** In states of starvation or Anorexia Nervosa, GH levels are often high due to GHRH stimulation and low IGF-1 (loss of negative feedback), but the specific TRH-induced paradoxical rise is characteristic of adenomatous tissue. * **Pituitary Adenoma:** This is a general term. While acromegaly is caused by a pituitary adenoma, not all pituitary adenomas (like non-functioning ones or gonadotropinomas) exhibit this specific GH response. **High-Yield Clinical Pearls for NEET-PG:** * **Oral Glucose Tolerance Test (OGTT):** The gold standard for diagnosing Acromegaly is the failure to suppress GH below 1 ng/mL after 75g of glucose [1]. * **Paradoxical Response to Glucose:** In some acromegaly patients, glucose may actually *increase* GH levels [1]. * **Best Screening Test:** Serum **IGF-1** levels (stable throughout the day, unlike GH which is pulsatile) [1]. * **Other conditions** showing paradoxical GH rise to TRH: Renal failure, Liver cirrhosis, and poorly controlled Diabetes Mellitus.

Question 1227: Hypercalciuria is seen in which of the following conditions?

A. Hyperparathyroidism
B. Vitamin D intoxication
C. Sarcoidosis
D. All of the above (Correct Answer)

Explanation: **Explanation:** Hypercalciuria (excessive urinary calcium excretion) occurs when the filtered load of calcium exceeds the renal tubular reabsorptive capacity. This is typically driven by hypercalcemia or defects in renal handling. 1. **Hyperparathyroidism (Option A):** Primary hyperparathyroidism is the most common cause of hypercalcemia [1]. While Parathyroid Hormone (PTH) actually *increases* calcium reabsorption in the distal tubule [2], the massive increase in bone resorption and intestinal absorption leads to a high filtered load of calcium that overwhelms the kidneys, resulting in net hypercalciuria [3]. 2. **Vitamin D Intoxication (Option B):** Excessive Vitamin D leads to increased intestinal calcium absorption and bone resorption. This suppresses PTH, which in turn decreases renal calcium reabsorption, leading to significant hypercalciuria [1]. 3. **Sarcoidosis (Option C):** In granulomatous diseases like sarcoidosis, macrophages express 1-alpha-hydroxylase, which converts 25-hydroxyvitamin D into active 1,25-dihydroxyvitamin D (Calcitriol) in an unregulated manner [2]. This mimics Vitamin D intoxication, causing hypercalcemia and subsequent hypercalciuria [1]. **Clinical Pearls for NEET-PG:** * **The "PTH Paradox":** Remember that while PTH is "calcium-sparing" for the kidneys, the **total** urinary calcium is high in hyperparathyroidism due to the sheer volume of calcium being filtered. * **Differential Diagnosis:** Always check the PTH level. If calcium is high and PTH is low, consider Sarcoidosis or Malignancy [1]. * **Complication:** Hypercalciuria is a major risk factor for the formation of calcium oxalate nephrolithiasis (kidney stones) [3]. * **Contrast:** Familial Hypocalciuric Hypercalcemia (FHH) is a key differential where you see hypercalcemia but **low** urinary calcium (due to a defective Calcium-Sensing Receptor) [1].

Question 1228: Osteoporosis is seen in which of the following conditions?

A. Thyrotoxicosis
B. Cushing's disease
C. Menopause
D. All of the above (Correct Answer)

Explanation: Osteoporosis is a skeletal disorder characterized by decreased bone mineral density (BMD) and micro-architectural deterioration, leading to increased bone fragility [3]. It can be primary or secondary to various endocrine disorders. * **Thyrotoxicosis (Option A):** Excess thyroid hormone (T3/T4) stimulates osteoclast activity more than osteoblast activity. This results in a high-turnover bone loss state, shortening the normal bone remodeling cycle and leading to a net loss of bone mass. * **Cushing’s Disease (Option B):** Chronic glucocorticoid excess is a potent cause of secondary osteoporosis [1]. It acts via multiple mechanisms: inhibiting osteoblast differentiation, increasing osteoclast survival, and decreasing intestinal calcium absorption (leading to secondary hyperparathyroidism) [1]. * **Menopause (Option C):** Estrogen deficiency is the most common cause of osteoporosis [4]. Estrogen normally inhibits bone resorption; its loss leads to increased cytokine levels (like IL-1, IL-6, and TNF-alpha) that activate osteoclasts via the RANK/RANKL pathway [2, 4]. Since all three conditions independently contribute to bone loss, **Option D (All of the above)** is the correct answer. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site of fracture:** Vertebral body (compression fractures), followed by the neck of the femur and Colles’ fracture [1]. * **Gold Standard Investigation:** Dual-energy X-ray absorptiometry (DEXA) scan. Osteoporosis is defined as a **T-score ≤ -2.5**. * **Drug of Choice:** Bisphosphonates (e.g., Alendronate, Zoledronic acid) are the first-line treatment. They work by inhibiting osteoclast-mediated bone resorption. * **Teriparatide:** A recombinant PTH analogue; it is the only anabolic agent that stimulates new bone formation.

Question 1229: Which of the following is NOT a cause of the clinical features of primary hyperaldosteronism?

A. Cushing syndrome
B. Adrenal adenoma
C. Adrenal hyperplasia
D. Chronic congestive cardiac failure (Correct Answer)

Explanation: To understand this question, one must distinguish between **Primary Hyperaldosteronism (Conn’s Syndrome)** and **Secondary Hyperaldosteronism**. [1] ### **Why Option D is Correct** **Chronic Congestive Cardiac Failure (CCF)** is a cause of **Secondary Hyperaldosteronism**. In CCF, there is decreased effective arterial blood volume, which reduces renal perfusion [2]. This triggers the **Renin-Angiotensin-Aldosterone System (RAAS)**, leading to high levels of **Renin** and subsequently high Aldosterone. In contrast, Primary Hyperaldosteronism is characterized by autonomous aldosterone production which **suppresses** renin levels. ### **Why the Other Options are Incorrect** * **Adrenal Adenoma (Option B):** Also known as Conn’s Syndrome, this is the most common cause of primary hyperaldosteronism (approx. 60-70%). * **Adrenal Hyperplasia (Option C):** Bilateral idiopathic adrenal hyperplasia is the second most common cause (approx. 30%). Both B and C involve autonomous secretion independent of the RAAS. * **Cushing Syndrome (Option A):** Certain forms of Cushing syndrome (especially ectopic ACTH or adrenal carcinomas) result in high levels of cortisol. At high concentrations, cortisol overwhelms the 11β-HSD2 enzyme and binds to mineralocorticoid receptors, mimicking the clinical features of primary hyperaldosteronism (hypertension and hypokalemia) [3]. ### **NEET-PG High-Yield Pearls** * **Screening Test:** Plasma Aldosterone Concentration (PAC) to Plasma Renin Activity (PRA) ratio. A **PAC:PRA ratio > 20-30** is suggestive of Primary Hyperaldosteronism. * **Classic Triad:** Hypertension, Hypokalemia, and Metabolic Alkalosis [1]. * **The "Escape" Phenomenon:** Patients with primary hyperaldosteronism do not usually have clinical edema due to "Aldosterone Escape," where increased proximal tubule sodium excretion compensates for distal reabsorption [2]. * **Drug of Choice:** Spironolactone (Aldosterone antagonist). For bilateral hyperplasia, medical management is preferred; for unilateral adenoma, surgical excision is the treatment of choice.

Question 1230: Thyrotoxicosis can be differentiated from anxiety neurosis clinically by?

A. Tachycardia
B. Sleeping pulse rate (Correct Answer)
C. Moist hands
D. Ankle's jerk

Explanation: The clinical differentiation between **Thyrotoxicosis** and **Anxiety Neurosis** is a classic NEET-PG topic, as both conditions present with sympathetic overactivity (palpitations, tremors, and sweating) [1]. **1. Why "Sleeping Pulse Rate" is the Correct Answer:** In **Anxiety Neurosis**, the tachycardia is reactive and mediated by acute stress; therefore, the heart rate typically returns to normal (below 80-90 bpm) during deep sleep when the emotional stimulus is removed. In **Thyrotoxicosis**, the tachycardia is caused by the direct effect of thyroid hormones on the myocardium (upregulation of beta-adrenergic receptors and direct genomic effects). Consequently, the **tachycardia persists even during sleep**. A sleeping pulse rate >90 bpm is highly suggestive of organic causes like hyperthyroidism. **2. Analysis of Incorrect Options:** * **Tachycardia (A):** Present in both conditions. While more persistent in thyrotoxicosis, the sign itself does not differentiate the two during an office visit. * **Moist Hands (C):** Both patients may have sweaty palms. However, a key differentiator is that the hands in thyrotoxicosis are **warm and moist** (due to peripheral vasodilation), whereas in anxiety, they are typically **cold and clammy** (due to vasoconstriction). * **Ankle Jerk (D):** While thyrotoxicosis is associated with a "brisk" or hyperreflexic tendon jerk, anxiety can also cause generalized hyperreflexia due to increased muscle tension. It is less specific than the sleeping pulse rate. **Clinical Pearls for NEET-PG:** * **Weight Loss:** Thyrotoxicosis presents with weight loss despite an **increased appetite**, whereas anxiety-related weight loss is usually associated with **decreased appetite** (anorexia). * **Eye Signs:** Presence of exophthalmos, lid lag, or lid retraction specifically points toward Graves' disease. * **The "Warmth" Factor:** If the question mentions "preference for cold weather" (heat intolerance), always lean toward Thyrotoxicosis.

Practice by Chapter

Diabetes Mellitus

Practice Questions

Thyroid Disorders

Practice Questions

Adrenal Gland Disorders

Practice Questions

Pituitary Disorders

Practice Questions

Calcium and Bone Metabolism

Practice Questions

Reproductive Endocrinology

Practice Questions

Lipid Disorders

Practice Questions

Endocrine Hypertension

Practice Questions

Multiple Endocrine Neoplasia

Practice Questions

Obesity and Metabolic Syndrome

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Neuroendocrine Tumors

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Endocrine Emergencies

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